Ceftolozane pharmaceutical compositions

ABSTRACT

Pharmaceutical compositions can include ceftolozane and an amount of sodium chloride effective to provide improved ceftolozane stability.

RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application No. 61/792,092, filed Mar. 15, 2013, and U.S. Provisional Patent Application No. 61/793,007, filed Mar. 15, 2013, both of which are incorporated herein in their entirety.

TECHNICAL FIELD

This disclosure relates to pharmaceutical compositions comprising ceftolozane.

BACKGROUND

Ceftolozane is a cephalosporin antibacterial agent. The antibacterial activity of ceftolozane is believed to result from its interaction with penicillin binding proteins (PBPs) to inhibit the biosynthesis of the bacterial cell wall which acts to stop bacterial replication. Antibacterial pharmaceutical compositions can include ceftolozane as a pharmaceutically acceptable salt formulated for intravenous administration. Ceftolozane sulfate is a pharmaceutically acceptable ceftolozane salt of formula (I) that can be formulated for intravenous administration or infusion.

The formulation of pharmaceutical compositions can be selected to minimize decomposition of the constituent drug substances and to produce a composition that is stable under a variety of storage conditions. A number of safe and effective injectable cephalosporin pharmaceutical compositions (e.g., as listed in FIG. 1, Table 1) comprise up to about 85 mg of sodium per gram of cephalosporin activity (i.e., 0-85 mg sodium per gram of cephalosporin activity).

In contrast, ceftolozane sulfate pharmaceutical compositions with similar levels of sodium (e.g., about 20-75 mg sodium from sodium chloride per gram of ceftolozane) exhibit undesirable levels of instability as measured by high pressure liquid chromatography (HPLC) during stability testing. For example, certain ceftolozane sulfate pharmaceutical compositions were characterized by at least 1.5-fold greater formation of an additional impurity identified by a retention time of 63 minutes (“RT63 Impurity”) during a stability study as disclosed herein. In addition, stability testing of ceftolozane pharmaceutical compositions with lower sodium levels also resulted in greater reduction in total ceftolozane purity.

Accordingly, there is a need for improved ceftolozane sulfate pharmaceutical compositions with greater stability, including improved pharmaceutical compositions that are not characterized by the RT63 Impurity after a three month stability test also described herein.

SUMMARY

The present disclosure provides ceftolozane pharmaceutical compositions with improved stability. The invention is based in part on the surprising discovery that ceftolozane in solid (e.g., powder) pharmaceutical compositions comprising about 1000 mg of ceftolozane active per 189 mg sodium from sodium chloride demonstrate improved chemical stability and purity compared with pharmaceutical compositions comprising ceftolozane with comparatively less sodium chloride. For example, the invention is based in part on the discovery of the absence of the RT63 Impurity in HPLC analysis of pharmaceutical compositions comprising about 1,000 mg of ceftolozane and 189 mg sodium from sodium chloride. By comparison, reducing sodium chloride relative to ceftolozane in tested compositions resulted in at least 1.5-fold greater impurity at RT=63 minutes (observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.). The ceftolozane formulations with reduced levels of sodium were not as stable as the ceftolozane formulation containing about 1,000 mg of ceftolozane per 189 mg sodium from sodium chloride. This includes preferred ceftolozane formulations containing an amount of ceftolozane per 189 mg of sodium from sodium chloride effective to maintain the level of RT63 Impurity below the detection limit (e.g., 0.03%) measured by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a table (Table 1) of FDA-approved parenteral cephalosporin antibiotic products, including the amount of sodium per 1 g of the cephalosporin antibiotic, as provided in the prescribing information.

FIG. 2 is a diagram of a lyophilization process that can be used to obtain a lyophilized ceftolozane composition comprising sodium chloride.

FIGS. 3A and 3B are chromatograms of ceftolozane drug substance obtained according to the analytical method described in Example 2.

FIG. 4 is a table (Table 2) of peaks for the ceftolozane prepared by a lyophilization process obtained by HPLC according to the analytical method of Example 2.

FIG. 5 is a table (Table 3a) showing the composition of various ceftolozane pharmaceutical compositions in which the sodium chloride concentration is varied.

FIG. 6 is a table (Table 3b) showing data obtained by HPLC for the RT 63 impurity as detected in the pharmaceutical compositions described in FIG. 5 containing ceftolozane.

FIG. 7 is a table (Table 4) showing the composition of various additional ceftolozane pharmaceutical compositions in which the sodium chloride content is varied.

FIG. 8 is a table (Table 5) showing the total purity of ceftolozane in the pharmaceutical compositions of FIG. 7, as measured by HPLC peak area according to the analytical method of described in Example 2.

FIG. 9 is a graph showing the total purity of certain pharmaceutical compositions disclosed in FIG. 7, as measured by HPLC peak area.

FIG. 10 is a table (Table 6) showing the composition of various ceftolozane pharmaceutical compositions in which the sodium chloride concentration is varied.

FIG. 11 is a table (Table 7) showing the purity of Ceftolozane in CXA-201 Compositions with varying amounts of sodium from sodium chloride at time zero, 1 day, 3 days and 7 days at 60° C.

FIG. 12 is a table (Table 8) showing purities of ceftolozane and a control (no excipient) in a lyophilized ceftolozane and sodium chloride composition at time zero, 1 day, 3 days and 7 days at 60° C., measured by HPLC.

DETAILED DESCRIPTION

Ceftolozane is the cephalosporin (6R,7R)-3-[(5-amino-4-{[(2-aminoethyl)carbamoyl]amino}-1-methyl-1H-pyrazol-2-ium-2-yl)methyl]-7-({(2Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(1-carboxy-1-methylethoxy)imino]acetyl}amino)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, and is also referred to as “CXA-101,” FR264205, or (6R,7R)-3-[5-Amino-4-[3-(2-aminoethyl)ureido]-1-methyl-1H-pyrazol-2-ium-2-ylmethyl]-7-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(Z)-1-carboxy-1-methylethoxyimino]acetamido]-3-cephem-4-carboxylic acid). Ceftolozane sulfate is a pharmaceutically acceptable salt of ceftolozane that can be combined with sodium chloride and other components to obtain an antibiotic composition suitable for administration by injection or infusion.

Surprisingly, pharmaceutical compositions comprising ceftolozane sulfate and about 1000 mg ceftolozane active per 189 mg sodium from sodium chloride exhibited unexpectedly improved chemical stability over the course of time and/or in the presence of heat, and less impurities than those pharmaceutical compositions comprising ceftolozane and less sodium chloride (e.g., see Example 3).

Pharmaceutical compositions comprising ceftolozane can be formulated to treat infections by parenteral administration (including subcutaneous, intramuscular, and intravenous) administration. Pharmaceutical compositions may additionally comprise excipients, pH adjusting additives (e.g., buffers) and the like. Non-limiting examples of these additives include citric acid and L-arginine. For example, L-arginine can be used to adjust pH and to increase the solubility of ceftolozane; and citric acid can be used to prevent discoloration of the product, due to its ability to chelate metal ions. In one particular embodiment, the pharmaceutical compositions described herein are formulated for administration by intravenous injection or infusion.

Pharmaceutical compositions comprising ceftolozane and sodium chloride can be obtained by lyophilization. As is known to those skilled in the art, lyophilization is a process of freeze-drying in which water is sublimed from a frozen solution of one or more solutes. Specific methods of lyophilization are described in Remington's Pharmaceutical Sciences, Chapter 84, page 1565, Eighteenth Edition, A. R. Gennaro, (Mack Publishing Co., Easton, Pa., 1990). A pharmaceutical composition comprising ceftolozane can be prepared by adding sodium chloride in a fixed ratio to ceftolozane in an aqueous solution prior to lyophilization. For example, the method can comprise the steps of: (1) forming a solution comprising sodium chloride and ceftolozane or a salt thereof followed by lyophilizing the solution; and (2) combining the lyophilized ceftolozane with other components (e.g., a β-lactamase inhibitor, such as tazobactam, or a lyophilized β-lactamase inhibitor, such as a lyophilized tazobactam) to obtain the pharmaceutical composition. The resulting pharmaceutical composition can be a powder for reconstitution to obtain an injectable pharmaceutical composition that can be intravenously administered to a patient. In yet a further embodiment, the method comprises adding about 1000 mg of ceftolozane active per 189 mg sodium from sodium chloride in an aqueous solution, then lyophilizing the solution to obtain a lyophilized material comprising sodium chloride and ceftolozane sulfate in a ratio effective to provide a product with less than 0.03% of the RT63 Impurity as detected by HPLC in Example 2.

Another embodiment of the invention is a vial containing a unit dosage form of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections. The vial can be obtained by a process comprising the steps of: a) lyophilizing an aqueous solution comprising about 1000 mg ceftolozane active in the form of ceftolozane sulfate per 189 mg sodium from sodium chloride and further comprising citric acid, and L-arginine to obtain a lyophilized ceftolozane composition; and b) filling a sufficient quantity of the lyophilized composition into a vial to obtain a unit dosage form comprising about 1,000 mg of ceftolozane active in the form of ceftolozane sulfate per 189 mg sodium from sodium chloride. In one aspect, the pH of the aqueous solution is 6.0 to 7.0. In another aspect the pharmaceutical composition is formulated for parenteral administration by reconstituting the pharmaceutical composition in the vial (e.g., with 10 mL of diluent such as water for injection or isotonic saline) followed by addition of the reconstituted pharmaceutical composition to a carrier for injection (e.g., about 100 mL of isotonic saline or other pharmaceutically acceptable carrier for intravenous administration). Optionally, the vial is also filled with tazobactam (e.g., a lyophilized tazobactam such as tazobactam sodium). In yet another aspect, the pharmaceutical composition is a solid (e.g., amorphous powder, crystal or combination thereof) obtained from a liquid composition comprising sodium chloride in an amount providing 189 mg sodium from sodium chloride, 1,000 mg of ceftolozane active and tazobactam in an amount providing about 500 mg tazobactam acid equivalent per 1,000 mg of ceftolozane active, the resulting solid pharmaceutical composition being formulated for parenteral administration and the pH of the aqueous solution is 6.0 to 7.0.

The pharmaceutical compositions can be administered for the treatment of infections, such as complicated intra-abdominal infections, complicated urinary tract infections (cUTIs) and pneumonia (e.g., community-acquired, hospital-acquired, etc). In one aspect, provided herein is a method for the treatment of bacterial infections in a mammal, comprising administering to said mammal a therapeutically effective amount of a pharmaceutical composition prepared according to the methods described herein. A method for the treatment of bacterial infections in a mammal can comprise administering to said mammal a therapeutically effective amount of a pharmaceutical composition comprising ceftolozane sulfate and sodium chloride. Non-limiting examples of bacterial infections that can be treated by the methods of the invention include infections caused by: aerobic and facultative gram-positive microorganisms (e.g., Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus pneumonia, Streptococcus pyogenes, Viridans group streptococci), aerobic and facultative gram-negative microorganisms (e.g., Acinetobacter baumanii, Escherichia coli, Haemophilus influenza, Klebsiella pneumonia, Pseudomonas aeruginosa, Citrobacter koseri, Moraxella catarrhalis, Morganella morganii, Neisseria gonorrhoeae, Proteus mirabilis, Proteus vulgaris, Serratia marcescens, Providencia stuartii, Providencia rettgeri, Salmonella enterica), gram-positive anaerobes (Clostridium perfringens), and gram-negative anaerobes (e.g., Bacteroides fragilis group (e.g., B. fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgates), Bacteroides distasonis, Prevotella melaninogenica). In certain embodiments of the methods described herein, bacterial infection is associated with one or more of the following conditions: complicated intra-abdominal infections, complicated urinary tract infections (cUTIs) and pneumonia (e.g., community-acquired, or nosocomial pneumonia). Community-acquired pneumonia (moderate severity only) can include infections caused by piperacillin-resistant, beta-lactamase producing strains of Haemophilus influenza. Nosocomial pneumonia (moderate to severe) caused by piperacillin-resistant, beta-lactamase producing strains of Staphylococcus aureus and by Acinetobacter baumanii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

As used herein, “treating,” “treat,” or “treatment” describes the management and care of a patient for the purpose of combating a disease, condition, or disorder and includes the administration of a pharmaceutical composition of the present invention to alleviate the symptoms or complications of a disease, condition or disorder, or to eliminate the disease, condition or disorder. The term “treat” can also include treatment of a cell in vitro or an animal model.

By a “therapeutically effective amount” of a compound of the invention is meant a sufficient amount of the compound to treat the disorder (e.g., bacterial infection). The specific therapeutically effective amount that is required for the treatment of any particular patient or organism (e.g., a mammal) will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific compound or composition employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts (see, for example, Goodman and Gilman's, “The Pharmacological Basis of Therapeutics”, Tenth Edition, A. Gilman, J. Hardman and L. Limbird, eds., McGraw-Hill Press, 155-173, 2001, which is incorporated herein by reference in its entirety). The therapeutically effective amount for a given situation can be readily determined by routine experimentation and is within the skill and judgment of the ordinary clinician.

Unless otherwise indicated, as used herein, the phrase “about 1000 mg ceftolozane” refers to an amount of ceftolozane that is considered a bioequivalent by the United States Food and Drug Administration (FDA), i.e. for which 90% CI of the relative mean Cmax, AUC(0-t) and AUC(0-∞) is within 80.00% to 125.00% of the reference formulation in the fasting state (see: “Guidance for Industry: Bioavailability and Bioequivalence Studies for Orally Administered Drug Products—General Considerations” Center for Drug Evaluation and Research, United States Food and Drug Administration, 2003).

As used herein, “189 mg sodium from sodium chloride per 1000 mg of ceftolozane” refers to a ratio of sodium from the sodium chloride to ceftolozane active. For example, “189 mg sodium from sodium chloride per 1000 mg of ceftolozane” includes, for example, 94.4 mg sodium from sodium chloride per 500 mg of ceftolozane, as well as, for example, 47.2 mg sodium from sodium chloride per 250 mg ceftolozane. In addition, “1,000 mg of ceftolozane as ceftolozane sulfate” refers to an amount of ceftolozane sulfate effective to provide 1,000 mg of ceftolozane. “189 mg sodium from sodium chloride” refers to the amount of sodium chloride (e.g., 480 mg) effective to provide 189 mg of sodium. The amount of sodium from sodium chloride per gram of ceftolozane activity in a pharmaceutical composition containing ceftolozane sulfate, chloride and sodium chloride can be calculated using the relevant molecular weights of ceftolozane, ceftolozane sulfate, sodium chloride and sodium. For example, a composition comprising about 1,147 mg ceftolozane sulfate and 189 mg sodium from sodium chloride contains 480 mg sodium chloride per 1,000 mg ceftolozane active.

As used herein, “1000 mg ceftolozane” refers to an amount of ceftolozane that is considered a bioequivalent by the United States Food and Drug Administration (FDA), i.e. for which 90% CI of the relative mean Cmax, AUC(0-t) and AUC(0-∞) is within 80.00% to 125.00% of the reference formulation in the fasting state (see: “Guidance for Industry: Bioavailability and Bioequivalence Studies for Orally Administered Drug Products—General Considerations”. Center for Drug Evaluation and Research, United States Food and Drug Administration, 2003).

A pharmaceutical composition can comprise ceftolozane in the form of ceftolozane sulfate and 189 mg sodium from sodium chloride per 1,000 mg of ceftolozane. The pharmaceutical composition of can further comprise L-arginine. The pharmaceutical composition can further comprise citric acid. The pharmaceutical composition can further comprise a lyophilized composition of the ceftolozane in the form of ceftolozane sulfate and the sodium from the sodium chloride. The pharmaceutical composition can also comprise 189 mg sodium from sodium chloride, 1,000 mg of ceftolozane in the form of ceftolozane sulfate, and further comprise L-arginine and citric acid.

Illustrative Examples of Selected Embodiments of the Invention Example 1 Manufacturing Procedure of Bulk (Tray) Lyophilized Ceftolozane

There are four main steps in the manufacture of CXA-101 bulk drug product: dissolution, sterile filtration, bulk lyophilization, and packaging into Sterbags®. These four main steps are composed of a total of 20 minor steps. The CXA-101 bulk drug product manufacturing process is presented below.

-   I. Dissolution     -   1. The prescribed amount of WFI is charged into the dissolution         reactor.     -   2. A prescribed amount of citric acid is added.     -   3. The solution is cooled at 5° C. to 10° C.     -   4. A prescribed amount of CXA-101 drug substance is added to the         solution.     -   5. A prescribed amount of L-arginine is slowly added to the         solution.     -   6. A check for complete dissolution is performed. Solution pH is         verified to be in the target range of 6.5 to 7.0.     -   7. A prescribed amount of sodium chloride is added to the         solution.     -   8. A check for complete dissolution is performed. Solution pH is         verified to be in the target range of 6.0 to 7.0. If the pH is         out of this range adjust with either L-Arginine or citric acid.     -   9. WFI is added to bring the net weight to 124.4 kg and the         solution is mixed well.     -   10. Samples are withdrawn for testing of final pH. -   II. Sterile filtration     -   11. The solution is passed through the filter (pore size 0.45         μm) followed by double filters (pore size 0.22 μm) onto a shelf         on the Criofarma lyophilizer.     -   12. The line is washed with WFI.     -   13. The washing solution is passed from Step 12 through sterile         filtration. -   III. Bulk lyophilization     -   14. The washing solution is loaded onto a separate shelf in the         lyophilizer (and later discarded).     -   15. The solution is lyophilized until dry.     -   16. The product shelf is cooled to 20° C.±5° C. -   IV. Packaging into Sterbags®     -   17. The lyophilized bulk drug product powder is milled.     -   18. The milled powder is sieved.     -   19. The sieved powder is blended for 30 minutes.     -   20. The powder is then discharged into Sterbags®

Prefiltration and Sterile-Filtration

Filtrate the compounded solution with a sterile tilter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter (Durapore®, Millipore) and a 0.1 urn polyvinylidene fluoride membrane filter (Durapore®, Millipore) connected in tandem. Confirm the integrity of each filter before and after the filtration. Take approximately 100 mL of the filtrate in order to check bioburden.

Filter the prefiltered compounded solution through a sterile filter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter and a 0.1 urn polyvinylidene fluoride membrane filter connected in tandem, and introduce the final filtrate into an aseptic room. Confirm the integrity of each filter before and after the filtration.

1.3. Processing of Vial, Stopper and Flip-off Cap

Wash a sufficient quantity of 28 mL vials with water for injection and sterilize the washed vials by a dry-heat sterilizer. Then transfer the sterilized vials into a Grade A area located in an aseptic room.

Wash a sufficient quantity of stoppers with, water for injection. Sterilize and dry the washed stoppers by steam sterilizer. Then transfer the sterilized stoppers into a Grade A area located in an aseptic room.

Sterilize a sufficient quantity of flip-off caps by steam sterilizer. Then transfer the sterilized flip-off caps into a Grade A or B area located in an aseptic room.

Filling and Partially Stoppering

Adjust the fill weight of the filtered compounded solution to 11.37 g (corresponds to 10 mL of the compounded solution), then start filling operation. Check the filled weight in sufficient frequency and confirm it is in target range (11.37 g±1%, 11.26 to 11.43 g). When deviation from the control range (11.37 g±2%, 11.14 to 11.59 g) is occurred, re-adjust the filling weight.

Immediately after a vial is filled, partially stopper the vial with a sterilized stopper. Load the filled and partially stoppered vials onto the shelves of a lyophilizer aseptically.

Lyophilization to Crimping, Visual Inspection, Labeling and Packaging

After all filled and partially stoppered vials are loaded into a lyophilizer, start the lyophilization program shown in FIG. 2. Freeze the loaded vials at −40° C. and keep until all vials freeze. Forward the program to primary drying step (shelf temperature; −20° C., chamber pressure; 100 to 150 mTorr). Primary drying time should be determined by monitoring the product temperature. Forward the program to secondary drying step (shelf temperature; 30° C., chamber pressure; not more than 10 mTorr) after completion of the primary drying step. After all vials are dried completely, return the chamber pressure to atmospheric pressure with sterilized nitrogen. Then stopper vials completely.

Unload the lyophilized vials from the chamber and crimp with sterilized flip-off caps.

Subject all crimped vials to visual inspection and label and package all passed vials.

Example 2 Analytical HPLC Method A. Operative Conditions

Column Develosil ODS-UG-5; 5 μm, 250 × 4.6 mm (Nomura Chemical, Japan) Mobile phase Sodium Perchlorate Buffer Solution (PH 2.5)/ CH₃CN 90:10 (vlv) Flow rate 1.0 mL/min Wavelength 254 nm Injection volume 10 μL Oven Temperature 45° C. Run Time 85 minutes Gradient Profile: Time (min) A % B % 0 75 25 30 70 30 60 0 100 85 0 100 85.1 75 25 110 75 25 B. Mobile phase preparation.

Sodium Perchlorate Buffer Solution was made by dissolving 14.05 g of sodium perchlorate Monohydrate in 1000.0 mL of water followed by adjusting pH to 2.5 with diluted perchloric acid (1 in 20).

Mobile Phase was then made by mixing Sodium Perchlorate Buffer Solution (pH 2.5) and acetonitrile in the ratio 90:10 (v/v).

Sodium Acetate Buffer Solution pH 5.5 (Diluent) was made by dissolving 1.36 g of sodium acetate trihydrate in 1000.0 mL of water followed by adjusting to pH 5.5 with diluted acetic acid (1 in 10).

C. Sample Preparation.

Sample solution: dissolve 20.0 mg, exactly weighed, of Sample, in 20.0 mL of water (Prepare just before injection into HPLC system).

System Suitability Solution (1%): take 1.0 mL of the Sample Solution (use first sample if more are present) and transfer into a 100.0 mL volumetric flask, dilute with water to volume and mix.

D. HPLC Analysis Procedure

-   1. Inject Blank (water) -   2. Inject System Suitability Solution and check for tailing factor     and theoretical plate number for CXA-101 peak:     -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000 -   3. Inject Sample Solution -   4. Inject System Suitability Solution and check for tailing factor     and theoretical plate number for CXA-101 peak.     -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000 -   5. Identify the peaks of Related Substances in the Sample     chromatogram based on the reference chromatogram reported in FIGS.     3A and 3B or, alternatively, on the basis of the RRT (Retention Time     Relative to CXA-101) values reported in Table 2 (FIG. 4)

E. Calculations

-   I. Report for each related substance its amount as expressed by area     percent.

$C_{i} = \frac{A_{i} \times 100}{A_{t} + {\sum A_{i}}}$

-   -   wherein:     -   C_(i)=Amount of related substance i in the Sample, area %     -   A_(i)=Peak area of related substance i in the Sample         chromatogram     -   A_(t)=Area of CXA-101 peak in the Sample chromatogram     -   A_(t)+ΣA_(i)=Total peaks area in the Sample chromatogram

Consider as any Unspecified Impurity, each peak in the chromatogram except CXA-101, peaks from 1 to 11 and every peak present in the blank chromatogram and report the largest.

-   II. Report the total impurities content as expressed by the     following formula:

$C_{T} = \frac{A_{i} \times 100}{A_{t} + {\sum A_{i}}}$

-   -   wherein:     -   C_(T)=total impurities content in the Sample, area %     -   A_(t)=area of CXA-101 peak in the sample chromatogram     -   ΣA_(i)=total peak areas of impurities in the sample chromatogram

Example 3 Increasing the Amount of Sodium Chloride Stabilizes Ceftolozane Pharmaceutical Compositions

Multiple stability studies were performed on ceftolozane sulfate, wherein the effect of varying amounts of sodium chloride on the stability of ceftolozane was examined.

The amount of sodium per mg of sodium chloride can be calculated (as known to one of ordinary skill in the art) based on the relative molar weight ratio of sodium and sodium chloride (e.g., 50 mg sodium chloride contains about 20 mg of sodium, etc).

The amount of ceftolozane in ceftolozane sulfate can similarly be calculated based on the respective molecular molar weights of ceftolozane and ceftolozane sulfate (e.g., 1,147 mg ceftolozane sulfate contains about 1,000 mg of ceftolozane). Accordingly, a composition comprising about 1,147 mg ceftolozane sulfate and 480 mg of sodium chloride also contains 480 mg of sodium chloride per 1,000 mg of ceftolozane.

A. Reduction of the Impurity at RT=63 Minutes

A stability study was carried out at 25° C. as described above. High, mid, and low salt formulations contained 189, 49.2 and 24.6 mg sodium from sodium chloride (480, 125, and 62.5 mg sodium chloride) per 1000 mg ceftolozane active, respectively. Compositions of blend Drug Product are listed in Table 3a in FIG. 5. Test results are summarized in Table 3b in FIG. 6.

Conclusion: At the three month time point, the reduced salt formulations were observed to be not as stable as the full salt formulation; and trends indicate that reduction in salt causes at least 1.5-fold greater impurity at RT=63 minutes (HPLC).

B. CXA-101 Peak Trends with NaCl

A stability study was carried out at 60° C. as described above. Sodium chloride content in test samples is described in Table 4 (FIG. 7). The results are provided in Table 5, FIG. 8 and the graph in FIG. 9. These results show that less total impurities were formed in the presence of 189 grams sodium from sodium chloride (481 grams sodium chloride) than with 74.7, 49.2, 29.5 or 19.7 mg sodium from sodium chloride (190.0, 125.0, 75.0 or 50.0 mg sodium chloride) per gram CXA-201 at 1, 3 and 7 days at 60° C./60% relative humidity.

C. Improvement in the Purity of Ceftolozane in CXA-201 Pharmaceutical Compositions with Varying Amounts of Sodium Chloride

A stability study was carried out at 60° C. as described above. The sodium chloride content in the CXA-201 compositions is described in Table 6 in FIG. 10. The HPLC data at 60° C. are summarized in Table 7 in FIG. 11.

Example 4 Screening of Stabilizing Agents

Sodium chloride was screened as a stabilizing agent. The purity of the ceftolozane in a composition comprising 100 mg ceftolozane and 100 mg of sodium chloride after 3 days at 60° C. was compared to a composition comprising 100 mg cefolozane comprising no stabilizing agent.

As shown in Table 8, FIG. 12, the ceftolozane composition comprising sodium chloride was demonstrated to be more stable than the ceftolozane composition comprising no stabilizing agent. 

1. A pharmaceutical composition comprising about 1,000 mg of ceftolozane active per 189 mg sodium from sodium chloride, and not more than 0.03% by high performance liquid chromatography (HPLC) of a RT63 Impurity at a retention time of about 63 minutes observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C., the pharmaceutical composition obtained by a process comprising the step of lyophilizing an aqueous solution comprising sodium chloride and ceftolozane sulfate to obtain a lyophilized ceftolozane composition, and formulating the pharmaceutical composition from the lyophilized ceftolozane composition.
 2. The pharmaceutical composition of claim 1, wherein the pharmaceutical composition comprises a total of about 1,000 mg of ceftolozane active.
 3. A pharmaceutical composition obtained by a process comprising the step of lyophilizing an aqueous solution comprising about 1,000 mg of ceftolozane per 189 mg sodium from sodium chloride, to obtain a lyophilized ceftolozane composition.
 4. The pharmaceutical composition of claim 3, wherein the pH of the aqueous solution is 6.0 to 7.0 and the aqueous solution further comprises L-arginine.
 5. The pharmaceutical composition of claim 3, wherein pharmaceutical composition is formulated for parenteral administration and further comprises citric acid.
 6. The pharmaceutical composition of claim 3, wherein the composition is a unit dosage form in a vial comprising tazobactam and 189 mg sodium from sodium chloride per 1,000 mg of ceftolozane active in the form of ceftolozane sulfate.
 7. The pharmaceutical composition of claim 3, wherein a. the aqueous solution further comprises L-arginine and citric acid; b. the pH of the aqueous solution is 6.0 to 7.0 prior to lyophilization; and c. the pharmaceutical composition further comprises tazobactam blended with the lyophilized ceftolozane composition.
 8. A unit dosage form container containing a unit dosage form of a pharmaceutical composition formulated for parenteral administration for the treatment of one or more infections selected from the group consisting of: complicated intra-abdominal infections, complicated urinary tract infections and pneumonia infections, the pharmaceutical composition comprising about 1,000 mg ceftolozane active in the form of ceftolozane sulfate per 189 mg sodium from sodium chloride.
 9. The unit dosage form container of claim 8, comprising the ceftolozane sulfate, tazobactam and the sodium chloride and not more than 0.03% by high performance liquid chromatography (HPLC) of a RT63 Impurity at a retention time of about 63 minutes observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.
 10. The unit dosage form container of claim 8 in the form of a bag or vial.
 11. The unit dosage form container of claim 8, containing a total of about 1,000 mg of ceftolozane active.
 12. The unit dosage form container of claim 8, containing a total of about 2,000 mg of ceftolozane active.
 13. The unit dosage form of claim 12 for the treatment of pneumonia.
 14. The unit dosage form container of claim 11 in the form of a bag or vial.
 15. The pharmaceutical composition of claim 3, comprising ceftolozane sulfate, sodium chloride and further comprising tazobactam, the pharmaceutical composition comprising not more than 0.03% by high performance liquid chromatography (HPLC) of a RT63 Impurity at a retention time of about 63 minutes observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.
 16. A method of manufacturing a ceftolozane composition having not more than 0.03% of a RT63 impurity as measured by high performance liquid chromatography (HPLC) of a RT63 Impurity at a retention time of about 63 minutes observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C., the method comprising the step of lyophilizing an aqueous solution comprising about 1,000 mg of ceftolozane per 189 mg sodium from sodium chloride, to obtain the ceftolozane composition.
 17. The product of the process of claim 16, containing a total of 1,000 mg ceftolozane in a unit dosage form container. 